const mongoose = require('mongoose')
mongoose.connect('mongodb://localhost:27017/mougujie', {
  useNewUrlParser: true,
  useUnifiedTopology: true
})

const db = mongoose.connection

db.once('open', () => {
  console.log('数据库连接成功');
})
db.on('error', () => {
  console.log('数据库连接失败');
})